Monday, July 30, 2007

Disturbingly, it seems that I may be a kidult. Comedian Richard Herring claims to be one such, and I nodded my head, and emitted empathic murmurs at numerous points in his article. I particularly enjoyed the following:

For your first [insert age] years you’re struggling up the steep slopes, heading for the top as fast as possible, not even looking around you, desperate to see what’s on the other side. Finally you are at the summit and get a clear view both ahead and behind.

You look back and you see a lush, fecund valley full of cavorting young people who wanted to be your friends, but ahead of you is a sheer cliff dropping into a stony, icy crevasse, littered with the bodies of the dead and dying. You want to turn round and do the climb again at a leisurely pace, but you are manhandled into a toboggan and sent whizzing down the slope. You might get thrown off at any point and die or get to the bottom and die. All that is certain is you are going to die, soon, along with all the other idiots who rushed to get over the hill only to find that the hill was what it was all about.

Saturday, July 28, 2007

The Friedmann-Robertson-Walker (FRW) models of general relativistic cosmology represent the spatial universe to be homogeneous and isotropic. This means, respectively, that each point in space is indistinguishable from any other, and at each point all the spatial directions are indistinguishable. Up to now, astronomical observations have suggested that the FRW models are correct. The distribution of galaxies appear to be isotropic on sufficiently large length-scales, and, at first sight, the temperature variations in the cosmic microwave background radiation (CMBR) also appeared to be isotropic.

However, in the past few years, detailed analysis of those temperature variations have revealed some anomalies. In particular, it appears that there is a preferential axis to those temperature variations, dubbed the 'Axis of Evil'. The temperature variation in the CMBR is expressed as a function upon the inner surface of our celestial sphere, δT(θ,φ). θ and φ are the angular coordinates upon the sphere, of which the temperature variation δT is a function. Like any function upon a sphere, it can be decomposed into a sum of the 'spherical harmonics' Yml(θ,φ). The spherical harmonics are essentially trigonometric functions upon the sphere.

Physicists tend to refer to the terms in a spherical harmonic decomposition as 'modes'. The term corresponding to l=0 is referred to as the monopole term, l=1 terms are called dipole terms, l=2 terms are quadrupole terms, etc. A dipole anisotropy in the temperature of the CMBR is a periodic variation which completes 1 cycle around the sky; it has one 'hot' pole and one 'cold' pole. A quadrupole anisotropy is a periodic variation in the temperature of the CMBR which completes 2 cycles around the sky. Mode l anisotropies complete l cycles around the sky. Higher l modes correspond to temperature fluctuations on smaller angular scales. After subtracting the effects of the Earth's diurnal rotation, its orbit around the Sun, the motion of the Sun within the Milky Way galaxy, and the motion of the Milky Way within the Local Group, we observe from the Earth a dipole anisotropy in the CMBR upon the celestial sphere. This is a dipole anisotropy upon our own private celestial sphere due to the proper motion of the Local Group of galaxies towards the Virgo supercluster at approximately 600kms-1. This dipole temperature anisotropy is subtracted from the CMBR to leave a temperature pattern which should be isotropic in a statistical sense.

Unfortunately, it appears that the quadrupole and octopole modes (the l=2 and l=3 modes) are less than isotropic. Their respective cycles of hot and cold spots are only present in a particular plane of the sky, and the axes of these two planes are closely aligned. Intriguingly, these axes point in the general direction of the Virgo supercluster. If these alignments have occurred by chance, then they constitute 1-in-66 and 1-in-20 flukes, respectively.

Moreover, Michael Longo of the University of Michigan has now analysed 1660 spiral galaxies from the Sloan Digital Sky Survey, and found that their rotation axes mostly line up with the Axis of Evil. Longo estimates the probability of this happening by chance to be less than 0.4 per cent.

The fluctuations in the CMBR on the largest angular scales are purported to be the remnants of the primordial density fluctuations. These primordial fluctuations were purportedly stretched to the length scales necessary for the formation of galaxies and clusters of galaxies by inflation, the hypothesized period of exponential expansion which occurred early in the history of the universe. The Axis of Evil is potentially, therefore, a serious problem for inflation.

However, it should be noted that general relativistic cosmology is perfectly capable of embracing a non-isotropic spatial universe. Whilst the FRW models are spherically symmetric about each point in space, there is another class of spatially homogeneous models which are merely rotationally symmetric about each point. These models include the Kantowski-Sachs class of models. Whereas the spatial isotropy group at each point of a FRW model is SO(3), the spatial isotropy group of a rotationally symmetric model is SO(2). These rotationally symmetric models are still homogeneous, so each point in space is rotationally symmetric about some axis.

So far, attempts to explain away the Axis of Evil as the consequence of contamination of the CMBR data by foreground processes have been unsuccessful. Nevertheless, the fact that the Axis of Evil points towards the Virgo supercluster also seems to be a remarkable coincidence if it occurred by chance. Perhaps local processes, related to the motion of the Local Group towards the Virgo supercluster, have altered the dipole anisotropy from its calculated form. The consequence may be that we have not correctly subtracted the dipole anisotropy from the CMBR, thereby leaving a remnant in the quadrupole and octopole modes.

Thursday, July 26, 2007

There's no doubt that Grand Prix racing isn't as good as it used to be. Some people suggest that each generation makes this type of observation about its most cherished cultural items; your sporting heroes, your favourite music and your favourite films, they argue, tend to come from your youth, and that which comes thereafter seems inferior in comparison. This is a type of cultural relativism. The suggestion is that sport and music doesn't get better or worse, it merely changes. In the case of Grand Prix racing, at least, I would resist this conclusion.

Grand Prix racing in the 1970s and 1980s featured a variety of beautifully sculpted and proportioned cars, racing on challenging circuits with camber and gradient, varying radius turns, and fast corners, driven by a fascinating array of talented drivers. And they actually raced in those days: they overtook each other on the track, not in the pit-stops. These days, the cars look appalling, the circuits are flat, constant-radius, emasculated autodromes designed by computer, and, whilst the contemporary sport has three or four top drivers, there is little talent-in-depth.

The most dramatic, tragic, and tumultuous season of all was 1982, and I was therefore delighted to see that Christopher Hilton has written a book devoted to this Grand Prix season.

Hilton isn't the greatest writer in the pantheon of Formula 1 journalists, but this book is a corker. Hilton draws heavily upon the recollections of key players such as Keke Rosberg and John Watson, and, in combination with the intrinsic drama of the year, this makes for a rivetting read.

Tuesday, July 17, 2007

The priapic Cerne Abbas giant in Dorset, has been joined by a diaperic Homer Simpson! The giant is one of those chalk figures, not exactly inscribed into the hillside, but, given that the figure is formed by exposing the underlying chalk, it is perhaps 'exscribed'. There seem to be quite a few of these. I remember seeing the (Uffington) White Horse on the Berkshire Downs as a kid; I can recall walking round another one near Cirencester on a school-trip; there's one just outside Devizes in Wiltshire; and the Cerne Abbas one is somewhere to the North of Dorchester. Apparently, it's a tradition for young couples to visit the giant to ensure conception. Although, it's a bit of a trek, so, to save time, you could try drinking a couple of pints and not using a condom instead.

Monday, July 16, 2007

It seems that the Blandford 'vampire' Fly may be enjoying a renaissance. 73-year old retired journalist, Peter Dunn, of Bridport in Dorset, spent four days on an intravenous drip of powerful antibiotics after he was bitten by just such an airborne varmint. The larvae of this unusually sanguine fly breed in the weed beds of the slow-flowing River Stour, close to the town of Blandford. After emerging, the female fly seeks a refreshing haemoglobin repast, before mating. The female fly also enjoys nights out at the cinema, and nights in with a DVD and a bottle of wine. In 1988, more than 1,400 people were treated in hospital after being bitten by the sisterhood.

Blandford, in fact, is a rather unusual place all round. It's quintessential rural Dorset, but it's also heavily influenced by the presence of nearby Blandford Camp, home to the Royal Corps of Signals. So it's rather like a vector sum of Hardy's Wessex and Aldershot.

Sunday, July 15, 2007

Every gland in Victoria Coren's body is devoted towards the secretion of sexuality. Even the thyroid. An Oxford graduate, and daughter of Alan Coren, she once tried, with Charlie Skelton, to make the greatest hard-core porn film ever. This, in turn, inspired them to write the making-of book, Once more with feeling. More recently, Victoria presents Balderdash and Piffle, a BBC2 programme tracing the provenance of well-known words and phrases. Throughout these programmes, Vicky emanates simmering sensuality like a nuclear reactor emitting Cerenkov radiation, about to go critical. Even in the simple act of walking, she gyrates each hip erotically around the other.

Now, I wonder if Vicky would like to trace the origin of the term 'multiverse'. I first came across the term in a Terry Pratchett novel in the early 1990s, where it was used less than seriously. These days, however, it's used very seriously by cosmologists to refer to a hypothetical multiplicity of universes. An article in Nature this week attributes the coining of the term to science-fiction author Michael Moorcock, but Wikipedia attributes its origin to William James, and suggests that Michael Moorcock merely popularised it.

Wednesday, July 11, 2007

A new study published in Proceedings of the Royal Society A, confirms that neither variations in solar output, nor variations in the flux of cosmic rays, are capable of explaining the rise in global temperatures since 1980. The flip-side to this coin, however, is that the pattern of greenhouse gas emissions is equally incapable of explaining the temperature profile of the twentieth century up to 1970. Global temperatures increased up until 1940, despite a negligible increase in greenhouse gas emissions, and temperatures then decreased until about 1970. The pattern of solar activity explains the global temperature pattern very nicely up until 1970.

The obvious conclusion to an independent analyst is that both solar activity and anthropogenic emissions of greenhouse gases contribute to global temperature patterns. And yet the people on both sides of this debate seem congenitally incapable of acknowledging that both anthropogenic and non-anthropogenic factors have contributed to the rise in global temperature over the twentieth century.

Tuesday, July 10, 2007

I've started reading God is not Great, by Christopher Hitchens, and I have to say it's not as good as Dawkins's book, The God Delusion. First of all, there's a distinct and unavoidable feeling of deja vu . The Dawk was here first, and that's just the end of it. Take the following passage:

"Violent, irrational, intolerant, allied to racism and tribalism and bigotry, invested in ignorance and hostile to free inquiry, contemptuous of women and coercive toward children: organized religion ought to have a great deal on its conscience."

He's right, of course: most religion in most of the world, at most times in history, is just like this. The trouble is that Dawkins established something like the same proposition only six months or so ago. The other problem is that Hitchens uses a higher rhetoric-to-reason ratio than Dawkins. Like most journalists, Hitchens tries to convince by manipulating the emotions with anecdote and story; in contrast, Dawkins tries to convince by the use of reason. Notwithstanding these reservations, Hitchens does identify a few home truths about religion:

"The level of intensity fluctuates according to time and place, but it can be stated as a truth that religion does not, and in the long run cannot, be content with its own marvelous claims and sublime assurances. It must seek to interfere with the lives of nonbelievers, or heretics, or adherents of other faiths. It may speak about the bliss of the next world, but it wants power in this one. This is only to be expected. It is, after all, wholly man-made. And it does not have the confidence in its own various preachings even to allow coexistence between different faiths."

Saturday, July 07, 2007

It is, of course, Live Earth today, where a bunch of millionaires promote themselves, and tell us how we can save the world by being less wasteful. Not having a taste for humbug, I occupied myself otherwise during the day. In particular, I watched Hot Fuzz on DVD, the British comedy film starring Simon Pegg and Nick Frost, and directed by Edgar Wright. It was quite good, although, much like Shaun of the Dead, the previous film from this triumvirate, it isn't as funny as many of the critics suggested. It seems that pretty much any British film that's half-decent, receives excessive praise from British film critics. I wonder if this serves the interests of cinema-goers or the interests of the film critics...

It was noticeable that Edgar Wright still employs the same whizz-bang-snap editing technique that he used repeatedly in Spaced. And afficionados might also have spotted Julia Deakin, who plays the landlady, Marsha, in Spaced.

Tuesday, July 03, 2007

Noctilucent clouds are spooky, silvery-blue clouds which shine at night. Like cirrus cloud, they're composed of ice crystals, but they form at such a high altitude that, during the Summer months at least, they can be seen even after the sun has set.NASA's AIM satellite has just taken some images of noctilucent cloud distribution in the Northern hemisphere. It's claimed that the clouds are becoming brighter and more widespread, and one explanation for this is that the upper atmosphere may be cooling due to the energy being absorbed by increasingly abundant greenhouse gases in the lower atmosphere.

Monday, July 02, 2007

I've heard it said that true Radiohead fans hate Muse, perceiving them to be nothing more than Radiohead imitators. This is nonsense. Certainly, Muse picked up where Radiohead left off when Thom Yorke disappeared up his own posterior, but Muse have very much their own sound. Nevertheless, a decade on from OK Computer, comparison to Radiohead remains a touchstone of musical quality. And now the first album from Bournemouth band Air Traffic, Fractured Life, received the following glowing review in The Sunday Times:

This young quartet from Bournemouth are so much more musically savvy than nearly all the new crop of guitar bands that it will probably take the mad-for-it rock crowd a while to catch up with them. When they do, they will find this debut to be a richly coloured sequence of songs, comparable in scope and intensity to mid-1990s Radiohead. Beginning with a couple of hormonally overloaded rockers, Just Abuse Me and Charlotte, it shifts gears over the next nine tracks as vocalist/keyboard-player Chris Wall refracts his dark side through the hauntingly beautiful Empty Space, eventually regaining his equilibrium on Your Fractured Life. Performed with precision, conviction and, best of all, a poppy conciseness, this album is that often mentioned, rarely sighted thing: an emotional rollercoaster ride. Get on it.

But I'm not going to buy the album purely on the basis of one good tune that I've heard, and a review which compares them to Radiohead.

Sunday, July 01, 2007

The perspicacious Martin Brundle conducts an interesting interview with Ron Dennis, Chairman of the McLaren Group, in The Sunday Times. THE subject of conversation, of course, is Lewis Hamilton, and what Brundle describes as team-mate Alonso's emotional reaction to Hamilton's success. I particularly enjoyed the following paragraph:

So, Alonso is completely happy then, Ron? "Anyone is going to be happier if they’re leading the world championship than if they’re not. But that is being a competitive human being. He’s as happy as someone can be in his situation. But not as happy as he would be if he was leading." So, happy within the constraints of being someone who is not particularly happy, then.

Bryan Appleyard has secretly reviewed Frank Tipler's recent book, The Physics of christianity, for the Philadelphia Inquirer. The book review section of the Inquirer is edited by Frank Wilson, a contributor to Bryan's blog, and a fellow religious sympathiser. Nevertheless, I expected the review to be a little more scathing. Why not the Physics of islam, or the Physics of hinduism, or the Physics of Greek mythology? Tipler is quite potty, and although Bryan isn't in a position to adjudicate on the physics, I think he notices the extremity of Tipler's claims that "We have a theory of everything, all the problems were resolved 30 years ago...To deny the multiverse is to deny quantum theory; a complete theory of quantum gravity was stumbled upon long ago by Richard Feynman and Steven Weinberg."

Tipler claims that his salary is "some 40 percent lower than the average for a full professor at Tulane as a consequence of my belief." I seem to recall, however, that he has a second home in Florida, so things can't be too bad for someone who has now written two populist books at the interface of science and religion, both of which employ what might be termed a large degree of 'artistic license' with the physics.